Nuneham Viaduct shut - Didcot- Oxford

[themiller]

Not wishing to throw a hand grenade in among the celebrations, but do any informed forum members think that it’s only a matter of time until the other end of the viaduct will need the same (or similar) work carrying out?

 

[snowball]

Not wishing to throw a hand grenade in among the celebrations, but do any informed forum members think that it’s only a matter of time until the other end of the viaduct will need the same (or similar) work carrying out?

I haven't seen any mention of any subsidence or other problems there.

 

[EdChap]

I would guess that a couple of bods, with a bit of time to spare one day, had a look at the middle pier and the other abutment

 

[swt_passenger]

Not wishing to throw a hand grenade in among the celebrations, but do any informed forum members think that it’s only a matter of time until the other end of the viaduct will need the same (or similar) work carrying out?

AIUI only the problem pier is original (although refaced with matching brick), but the central pier, the north bank arched viaduct section and the main spans, all date from a later rebuild.

But post #300 has a good explanation of the sequence and dates…

 

[Peter Mugridge]

I haven't seen any mention of any subsidence or other problems there.

The north end is built on a different and much more solid ground - the geology changes literally underneath the river bed just past the area that caused the problems. There's something about that up thread somewhere.

 

[gavinro]

Not wishing to throw a hand grenade in among the celebrations, but do any informed forum members think that it’s only a matter of time until the other end of the viaduct will need the same (or similar) work carrying out?

I don't claim to be an "informed forum member". But would they have not done it at the same time if it was at all likely?

 

[railfan99]

Have we been told who (presumably at Network Rail) devised the overall Cunning Plan? And can forum members fill me in on how conversations with contractors would have gone?
For example, hello, is that TMS Maritime, can you pile into the river bed (the river is currently in rather a spate) to prop up this sagging bridge span by 20 April? You mean April 2024? No, next week ...

The funniest post I've read. But also very close to what a panicked call would be like if we had a transcript.

 

[zwk500]

I don't claim to be an "informed forum member". But would they have not done it at the same time if it was at all likely?

From all the comms put out, the worksite only appeared to cover the southern end so nothing would have been done (except maybe some visual inspections) on the other piers.

The funniest post I've read. But also very close to what a panicked call would be like if we had a transcript.

No it wouldn't, the transcript would have been much closer to 'we've got a bridge out south of Oxford, we need a piling team on site ASAP. What can you do for us, please?'

 

[themiller]

The north end is built on a different and much more solid ground - the geology changes literally underneath the river bed just past teh area that caused the problems. There's something about that up thread somewhere.

Thanks for that, Peter. It would have been a bit embarrassing to have got the wires up (at sometime in the future) and then found a problem with the north end.

 

[Nicholas43]

No it wouldn't, the transcript would have been much closer to 'we've got a bridge out south of Oxford, we need a piling team on site ASAP. What can you do for us, please?'

Ah, thanks, that does sound more like it! Any idea at what stage TMS would have worked out that they would put their kit in the river downstream at Abingdon lock, and tug/push it upstream to the site?

 

[zwk500]

Ah, thanks, that does sound more like it! Any idea at what stage TMS would have worked out that they would put their kit in the river downstream at Abingdon lock, and tug/push it upstream to the site?

No idea, sorry.

 

[Benjwri]

Hopefully electrification will be the only next closure.

Probably the blockades for the station rebuild, although maybe some freight will still run to Hinksey.

 

[The Planner]

Probably the blockades for the station rebuild, although maybe some freight will still run to Hinksey.

Oxford blockade in a few weeks and another one next year to sort Botley Road.

 

[Peter Mugridge]

Thanks for that, Peter. It would have been a bit embarrassing to have got the wires up (at sometime in the future) and then found a problem with the north end.

Very true - and let's hope that they DO get the wires up ( and that they don't stop at Oxford either, but that's for another thread! ).

Hmm... I've just spotted the typo I missed when I posted!

 

[DelW]

Full marks to NR and their various subcontractors and designers for the speed with which this scheme was devised, designed, procured and installed. It's really quite remarkable to have managed all that within around ten weeks.

I think it's quite innovative in the way the cill beams are attached to the piles, and in the way that the new abutment seems to separate the deck support from the embankment retaining wall. I wonder whether the layout might prove to be useable elsewhere even if there is less time pressure?

 

[InOban]

When the annual awards season comes round, I think we know where many awards are going....

 

[fandroid]

Looks like for the most part, all XC services are single units today, but are running to Bournemouth (no alternate hourly Reading terminators).

Great to see it open again

That's the May timetable change belatedly coming into force. South of Reading we've waited rather too long for reinstatement of hourly Crosscountry services

 

[Mcr Warrior]

Full marks to NR and their various subcontractors and designers for the speed with which this scheme was devised, designed, procured and installed. It's really quite remarkable to have managed all that within around ten weeks.

Had provisional bridge reconstruction plans already been prepared, some time in advance of the line having to be closed, but then delayed awaiting a sufficiently long period of track access?

 

[Jimini]

That's the May timetable change belatedly coming into force. South of Reading we've waited rather too long for reinstatement of hourly Crosscountry services

Aha, I see, thanks!

 

[DelW]

Had provisional bridge reconstruction plans already been prepared, some time in advance of the line having to be closed, but then delayed awaiting a sufficiently long period of track access?

That's possible, but I think that the treatment using grout injection was still the chosen solution up to the point where it subsided too far for that to work, which was the point when the line was closed. Only those directly involved will really know though, I'm just speculating from afar.

 

[Jimini]

Traversed it twice today. Very smooth! H/T to all involved!

 

[snowball]

H/T to all involved!

High tension?

 

[Jimini]

High tension?

Hat tip!

 

[railfan99]

How long is the 50mph/80kmh speed restriction likely to stay in place?

 

[mr_moo]

Normal duration after a track renewal is 1 week of 50mph TSR.
There should be a follow-up (SPATE*) tamp a week after opening, and as part of that they will measure how much the track has settled by. If it's small numbers they will probably up the speed. If it's larger numbers (There's a LOT of new fill there) they will probably leave it in place for another week or two.

FYI SPATE = Speed Previously Advised Terminated Early. To have a TSR (as opposed to an Emergency Speed Restriction), you need to publish it in the WON (Weekly Operating Notice), so drivers are aware of it. You'd normally publish this for longer than needed in case it needs to stay on, and then, when it's removed, you change the boards from a '50' to a '\' to tell the drivers it's been rescinded. Thus, the WON will most likely show a 50mph TSR being in place for many weeks, and they will rescind it when the monitoring shows sufficienly small settlement.

 

[Annetts key]

Oh no, don’t open that can of worms (when is a TSR not a TSR…).

But thanks for answering the question that was asked.

 

[12LDA28C]

How long is the 50mph/80kmh speed restriction likely to stay in place?

No need for the 'kmh', we use mph in the UK and imperial measurements are used on the railway for speed and distance with very limited exceptions.

 

[mr_moo]

Oh no, don’t open that can of worms (when is a TSR not a TSR…).

Fair point! Sorry!

 

[Annetts key]

No need for the 'kmh', we use mph in the UK and imperial measurements are used on the railway for speed and distance with very limited exceptions.

Yes, for most purposes imperial is used for speeds and distances. However, gauge is now metric, and new signalling systems/schemes are all metric including the distance from the datum and the spacing between signals/AWS/TPWS/ATP (we have to keep converting between km and miles & chains).

 

[12LDA28C]

However, gauge is now metric

Really? Interesting. I always knew it as four foot eight and a half, if I asked anyone I know what the UK standard gauge is that is the answer they would give. I appreciate someone who works in infrastructure planning, renewals and so on might have a different unit of measurement.

What's the reason behind using metric measurements for new schemes when the rest of the railway uses miles, chains and yards? When conversion has to take place between the two systems in the manner you describe that sounds like a recipe for disaster.